From the question given:
(a) Let x be the container that has been sold
Recall, Profit = Revenue - Cost
Total Profit = (4.25 - 2.5)x = 1.75x
Total Profit = Total Revenue - Total Cost
= 4.25x - 2.5x
= 1.75x
(b)
1.75 * 174
= 304.5 dollars
Total Profit = (4.25 * 174) - (2.5 * 174)
= 739.5 - 435
= 304.5 dollars.